David A Booth

US Patent:

7075445, Jul 11, 2006

Filed:

Aug 20, 2003

Appl. No.:

10/645354

Inventors:

David K. Booth - Tigard OR, US
Douglas H. Marman - Ridgefield WA, US
Gary E. Friar - Tigard OR, US

Assignee:

GE Security, Inc. - Bradenton FL

International Classification:

G08B 17/10

US Classification:

340630, 356338

Abstract:

A smoke detector of an obscuration type has an effective light propagation path of substantially greater length than the light propagation paths of conventional obscuration-type smoke detectors to provide increased smoke detection sensitivity without increased background noise or numbers of false alarm incidents. The smoke detector has a light source that emits a light beam that propagates into a detection chamber composed of first and second optical components having respective first and second opposed light reflecting surfaces. The light reflecting surfaces reflect the light beam across the detection chamber multiple times before the reflected light beam is incident on a light detector. The multiple reflections of the light beam increase its effective path length of propagation within the detection chamber to provide the increased smoke detection sensitivity.

US Patent:

7274356, Sep 25, 2007

Filed:

Oct 9, 2003

Appl. No.:

10/681330

Inventors:

Chi Man Charles Ung - Calgary, CA
David Kenneth Booth - Tigard OR, US
Stephen Worthington - Calgary, CA
Mark Andrew Fletcher - Calgary, CA
Roberto A. L. Sirotich - Calgary, CA

Assignee:

Smart Technologies Inc.

International Classification:

G06F 3/042
G06F 3/041
G06F 3/033
G09G 5/08

US Classification:

345158, 178 1809, 345173, 345175

Abstract:

An apparatus for detecting a pointer within a region of interest includes a first reflective element extending along a first side of the region of interest and reflecting light towards the region of interest. A second reflective element extends along a second side of the region of interest and reflects light towards the region of interest. The second side is joined to the first side to define a first corner. A non-reflective region generally in the plane of at least one of the first and second reflective elements is adjacent the first corner. At least one imaging device captures images of the region of interest including reflections from the first and second reflective elements.

US Patent:

8274496, Sep 25, 2012

Filed:

Oct 31, 2008

Appl. No.:

12/262221

Inventors:

Chi Man Charles Ung - Calgary, CA
David Kenneth Booth - Tigard OR, US
Roberto A. L. Sirotich - Calgary, CA

Assignee:

SMART Technologies ULC

International Classification:

G06F 3/042

US Classification:

345176, 345173, 178 1803, 178 1809

Abstract:

An apparatus for detecting a pointer includes a waveguide and a touch surface over the waveguide on which pointer contacts are to be made. At least one reflecting device extends along a first side of the waveguide and touch surface. The reflecting device defines an optical path between the interior of the waveguide and the region of interest above the touch surface. At least one imaging device looks across the touch surface and into the waveguide. The imaging device captures images of the region of interest and within the waveguide including reflections from the reflecting device.

US Patent:

8456418, Jun 4, 2013

Filed:

Jun 13, 2007

Appl. No.:

11/762198

Inventors:

Chi Man Charles Ung - Calgary, CA
David Kenneth Booth - Tigard OR, US
Stephen Worthington - Calgary, CA
Mark Andrew Fletcher - Calgary, CA
Roberto A. L. Sirotich - Calgary, CA

Assignee:

SMART Technologies ULC

International Classification:

G06F 3/033
G06F 3/042

US Classification:

345158, 345175

Abstract:

An apparatus for detecting a pointer within a region of interest includes a first reflective element extending along a first side of the region of interest and reflecting light towards the region of interest. A second reflective element extends along a second side of the region of interest and reflects light towards the region of interest. The second side is joined to the first side to define a first corner. A non-reflective region generally in the plane of at least one of the first and second reflective elements is adjacent the first corner. At least one imaging device captures images of the region of interest including reflections from the first and second reflective elements.

US Patent:

20050243070, Nov 3, 2005

Filed:

Apr 29, 2004

Appl. No.:

10/834190

Inventors:

Chi Ung - Calgary, CA
David Booth - Tigard OR, US
Roberto Sirotich - Calgary, CA

International Classification:

G09G005/00

US Classification:

345176000

Abstract:

An apparatus for detecting a pointer includes a waveguide and a touch surface over the waveguide on which pointer contacts are to be made. At least one reflecting device extends along a first side of the waveguide and touch surface. The reflecting device defines an optical path between the interior of the waveguide and the region of interest above the touch surface. At least one imaging device looks across the touch surface and into the waveguide. The imaging device captures images of the region of interest and within the waveguide including reflections from the reflecting device.

US Patent:

20090140868, Jun 4, 2009

Filed:

Dec 26, 2006

Appl. No.:

11/645816

Inventors:

David Booth - Tigard OR, US

International Classification:

G08B 17/10

US Classification:

340628

Abstract:

A smoke detection method includes ramp-counting of non-decreasing smoke level samples for detecting smoldering fire conditions and counting of obscuring smoke level samples for detecting other-than-smoldering fire conditions. The ramp-counting of non-decreasing smoke level samples includes increasing a smoke detection ramp count for each successive smoke level sample that does not decrease from a previous one and resetting the smoke detection ramp count whenever a smoke level sample decreases relative to a previous one.

US Patent:

20130120316, May 16, 2013

Filed:

Sep 25, 2012

Appl. No.:

13/626790

Inventors:

SMART TECHNOLOGIES ULC - Calgary, CA
David Kenneth Booth - Tigard OR, US
Roberto A.L. Sirotich - Calgary, CA

Assignee:

SMART TECHNOLOGIES ULC - Calgary

International Classification:

G06F 3/042

US Classification:

345175

Abstract:

An apparatus for detecting a pointer includes a waveguide and a touch surface over the waveguide on which pointer contacts are to be made. At least one reflecting device extends along a first side of the waveguide and touch surface. The reflecting device defines an optical path between the interior of the waveguide and the region of interest above the touch surface. At least one imaging device looks across the touch surface and into the waveguide. The imaging device captures images of the region of interest and within the waveguide including reflections from the reflecting device.

US Patent:

57424381, Apr 21, 1998

Filed:

Sep 16, 1994

Appl. No.:

8/307223

Inventors:

Arlie R. Conner - Tualatin OR
Jonathan R. Biles - Portland OR
David K. Booth - Tigard OR

Assignee:

In Focus Systems, Inc. - Wilsonville OR

International Classification:

G02B 308

US Classification:

359743

Abstract:

A projection system includes a collection lens that minimizes apparent magnification of the light source, so that the resulting system more nearly conforms to a point source idealization. Attendant benefits include improved collimation, a smaller projection lens, and a greater depth of focus. The collection lens is desirably of a "wrap around" configuration to maximize light collection while contributing to reduced source magnification. The opposite side of the collection lens can be provided with a convex lens of Fresnel form. Use of the Fresnel optic moves the principal plane of the collection lens closer to the light source, further minimizing the source's apparent magnification. The projection system additionally includes condensing optics formed with a deliberate asymmetry so as to provide more uniform illumination of a rectangular image plane. The Fresnel surface of the collection lens can be designed to provide this asymmetry.